1990 740 gle gas delivery problem?

joedrt77 · Post by **joedrt77** » 16 Oct 2016, 11:14

lummert wrote:I forgot to mention that I used heavy gauge wire and a 30 amp fuse for the jumper. try connecting the jumper from 30 to 87a which goes to the pumps. Then try 30 to 87b which goes to the rsr. Does the wire overheat in both tests.

My relay has 87-1 and 87-2 , did 30 to 87-2 that's the one that got very hot, by 30 to 87a you mean 87-1 on mine correct? thanks.

joedrt77 · Post by **joedrt77** » 16 Oct 2016, 12:47

Ok, did 30 to 87-1, no fuel pump sound, went back to 30 to 87-2, started with quickstart for about 2 seconds then died, jumper wire got hot again and smoked before I grabbed it off, used a sturdy paper clip, I'm thinking that points to the fp relay or the power stage maybe???

joedrt77 · Post by **joedrt77** » 16 Oct 2016, 12:54

joedrt77 wrote:
lummert wrote:I forgot to mention that I used heavy gauge wire and a 30 amp fuse for the jumper. try connecting the jumper from 30 to 87a which goes to the pumps. Then try 30 to 87b which goes to the rsr. Does the wire overheat in both tests.
My relay has 87-1 and 87-2 , did 30 to 87-2 that's the one that got very hot, by 30 to 87a you mean 87-1 on mine correct? thanks.

Was I suppose to get the fuel pump sound when I went 30 to 87-1, there was no fp sound, thanks.

joedrt77 · Post by **joedrt77** » 16 Oct 2016, 13:01

There's a grey wire that goes from the f injectors to the fuel control unit pin 18, any way to test pin 18 with multimeter? and a green n red wire to rsr relay #3 pin, any way to test that one?, thanks for direction, hope I'm getting close.

lummert · Post by **lummert** » 16 Oct 2016, 13:44

Which engine is in your 740 GLE? And yes, the terminals are 87/1 and 87/2.
The gray wire that connects to LH ECU pin 18 is what switches (pulses?) the ground to the injectors.

wiring diagrams:

http://www.volvowiringdiagrams.com

joedrt77 · Post by **joedrt77** » 17 Oct 2016, 13:04

lummert wrote:Which engine is in your 740 GLE? And yes, the terminals are 87/1 and 87/2.
The gray wire that connects to LH ECU pin 18 is what switches (pulses?) the ground to the injectors.

wiring diagrams:

http://www.volvowiringdiagrams.com

B234F, how do I test ecu pin 18? the procedure I mean, with either a test light or a multimeter, have both and can I test green n red wire to rsr relay #3 pin, just tried a new fuel injection relay, the 1 in the fuse box, same condition, thanks.

joedrt77 · Post by **joedrt77** » 17 Oct 2016, 13:33

does the power stage have anything to do with the injectors getting 12 v ? thanks.

lummert · Post by **lummert** » 17 Oct 2016, 15:43

LH ECM needs ignition signal.

joedrt77 · Post by **joedrt77** » 17 Oct 2016, 20:23

lummert wrote:LH ECM needs ignition signal.

does the ign. signal come from the power stage or the ign. control unit? Thanks.

joedrt77 · Post by **joedrt77** » 19 Oct 2016, 05:18

I'll get it eventually, thanks for the effort.

1990 740 gle gas delivery problem?

Re: 1990 740 gle gas delivery problem?